82/83 fork differences?

[jefferson]

It's really not the length of the lines, but the relationship of master to caliper piston size. Cars have much larger pistons in their calipers.

[Rikugun]

Indeed. I had quite a learning curve in that regard when I did my first single disk upgrade. The SV650 type caliper I used didn't have sufficient piston area to make the correct ratio using the stock 1/2" master.

[The Prophet of Doom]

Thanks for the input Rohan. After I posted and gave it a bit of serious thought the first question I had was the bleeding process.  That bit about the ability to "twist" the lines into alignment is a good point too - the longer the better. I knew there was a reason why I liked having you around here.

What about the added volume of fluid that has to be moved with 2 large lines? Any thoughts on that? I thought no real effect but then exaggerated the lengths as a thought experiment, say to 10' each.  Would that effect the feel at the lever? The culprit would be lack of efficiency/loss due to blow-by at the master cylinders piston. Cars have much greater length of line and hoses but they also a larger master piston. Maybe I'm over-thinking things. Again.

With virtually uncompressible liquids like brake fluid the losses from increased length are friction only.  Negligible even with fairly long lengths if they are well bled. 

Are you going to switch to DOT 5.1?

[Rikugun]

I haven't gotten that far yet. I haven't even begun looking for a 5/8" master cylinder yet. The 11 mm currently installed and the stock RJ 1/2" would be way to much.  Is DOT 5.1 what all the kids are using now? If so, I'll want to keep up with the times.

It wasn't compressibility I was worried about but rather the inherent inefficiencies of the master i.e. internal leaking past the cup. I'm sure I was over thinking it.  It's already been done successfully so no need to reinvent the wheel.

[The Prophet of Doom]

All the 16Rs have twin rotors.  I've never had an issue with brake blow-by.  Don't stress about it.   


Here's a source for what you need:
https://yambits.co.uk/xz550-brake-master-cylinder-p-103045.html

[Rikugun]

Wow, that's a nice looking pattern part. That's $65 in US greenbacks plus shipping. I think I can do better but I'll keep them in mind as a contingency plan.

[injuhneer]

The XJ Yamahas had a single line to a distribution block (manifold) on the lower triple clamp. Works a treat. Equal length lines to each side with one from the master. No twist. No routing problems.

https://www.ebay.com/itm/Yamaha-XJ-650-4K0-Bj-1980-Brake-line-distributor-N1795/402124035720?hash=item5da075d688:g:bm8AAOSwT-NeV6MR